Practical Design Calculations for Groundwater and Soil Remediation Jeff Kuo, Ph. Civil and Environmental Engineering Department California State University Fullerton ©1999 CRC Press LLC Library of Congress Cataloging-in-Publication Data Kuo, Jeff. Practical design calculations for groundwater and soil remediation / Jeff Kuo. Includes bibliographical references and index. Soil remediation—Mathematics—Problems, exercises, etc. Groundwater—Purification—Mathematics—Problems, exercises, etc.1′68—dc21 98-28646 CIP This book contains information obtained from authentic and highly regarded sources. Reprinted material is quoted with permission, and sources are indicated. A wide variety of references are listed. Reasonable efforts have been made to publish reliable data and information, but the author and the publisher cannot assume responsibility for the validity of all materials or for the consequences of their use. 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Government works International Standard Book Number 1-56670-238-0 Library of Congress Card Number 98-28646 Printed in the United States of America 1 2 3 4 5 6 7 8 9 0 Printed on acid-free paper ©1999 CRC Press LLC About the author Jeff (Jih-Fen) Kuo worked in environmental engineering industries for over 10 years before joining the Department of Civil and Environmental Engi- neering at California State University, Fullerton, in 1995. He gained his industrial experiences from working at Groundwater Technology, Inc. (now Flour-GTI), Dames and Moore, James M. Montgomery Consulting Engineers (now Montgomery–Watson), Nan-Ya Plastics, and the Los Angeles County Sanitation Districts. His industrial experiences in environmental engineering include design and installation of air strippers, activated carbon adsorbers, flare/catalytic incinerators, and biological systems for groundwater and soil remediation; site assessment and fate analysis of toxics in the environment; RI/FS work for landfills and Superfund sites; design of flanged joints to meet stringent fugitive emission requirements; air emissions from waste- water treatment; and wastewater treatment. Areas of research in environ- mental engineering include dechlorination of halogenated aromatics by ul- trasound, fines/bacteria migration through porous media, biodegradability of bitumen, surface properties of composite mineral oxides, kinetics of acti- vated carbon adsorption, wastewater filtration, THM formation potential of ion exchange resins, and UV disinfection. degree in chemical engineering from National Taiwan University, an M. degree in chemical engineering from the University of Wyoming, an M. in petroleum engineering, and an M. in Environmental Engineering from the University of Southern California. He is a professional civil, mechanical, and chemical engineer registered in California. ©1999 CRC Press LLC to my wife Kathy, daughters Emily and Whitney, and my mom ©1999 CRC Press LLC Contents Chapter I Introduction I.1 Background and Objectives I.3 How to Use this Book Chapter II Site Characterization and Remedial Investigation II.1 Determination of the Extent of Contamination II.1 Mass and Concentration Relationship II.2 Amount of Soil from Tank Removal or Excavation of Contaminated Area II.3 Amount of Contaminated Soil in the Vadose Zone II.4 Mass Fractiona and Mole Fraction of Components in Gasoline II.5 Height of the Capillary Fringe II.6 Estimating the Mass and Volume of the Free-Floating Product II.7 Determination of the Extent of Contamination — A Comprehensive Example Calculation II.2 Soil Borings and Groundwater Monitoring Wells II.1 Amount of Cuttings from Soil Boring II.2 Amount of Packing Materials and/or Bentonite Seal29 II.3 Well Volume for Groundwater Sampling II.3 Mass of Contaminants Present in Different Phases II.1 Equilibrium Between Free Product and Vapor II.2 Liquid–Vapor Equilibrium II.3 Solid–Liquid Equilibrium II.4 Solid–Liquid–Vapor Equilibrium II.5 Partition of Contaminants in Different Phases Chapter III Plume Migration in Groundwater and Soil III.1 Groundwater Movement III.1 Darcy’s Law ©1999 CRC Press LLC III.2 Darcy’s Velocity vs. Seepage Velocity III.3 Intrinsic Permeability vs. Hydraulic Conductivity III.4 Transmissivity, Specific Yield, and Storativity III.5 Determine Groundwater Flow Gradient and Flow Direction III.2 Groundwater Pumping III.1 Steady-State Flow in a Confined Aquifer III.2 Steady-State Flow in an Unconfined Aquifer III.3 Aquifer Test III.1 Theis Method III.2 Cooper–Jacob Straight-Line Method III.3 Distance–Drawdown Method III.4 Migration Velocity of the Dissolved Plume III.1 The Advection–Dispersion Equation III.2 Diffusivity and Dispersion Coefficient III.3 Retardation Factor for Migration in Groundwater III.4 Migration of the Dissolved Plume III.5 Contaminant Transport in the Vadose Zone III.1 Liquid Movement in the Vadose Zone III.2 Gaseous Diffusion in the Vadose Zone III.3 Retardation Factor for Vapor Migration in the Vadose Zone Chapter IV Mass Balance Concept and Reactor Design IV.1 Mass Balance Concept IV.2 Chemical Kinetics IV.1 Rate Equations IV.2 Half-Life IV.3 Types of Reactors IV.1 Batch Reactors IV.4 Sizing the Reactors IV.5 Reactor Configurations IV.1 Reactors in Series IV.2 Reactors in Parallel Chapter V Vadose Zone Soil Remediation V.1 Soil Vapor Extraction V.2 Expected Vapor Concentration V.3 Radius of Influence and Pressure Profile V.4 Vapor Flow Rates V.5 Contaminant Removal Rate ©1999 CRC Press LLC V.7 Effect of Temperature on Soil Venting V.8 Number of Vapor Extraction Wells V.9 Sizing of Vacuum Pump (Blower) V.1 Description of the Soil Bioremediation Process V.3 Soil Washing/Solvent Extraction/Soil Flushing V.1 Description of the Soil Washing Process V.4 Low-Temperature Heating (Desorption) V.1 Description of the Low-Temperature Heating (Desorption) Process V.2 Design of the Low-Temperature Heating (Desorption) Process Chapter VI Groundwater Remediation VI.1 Hydraulic Control (Groundwater Extraction) VI.1 Cone of Depression VI.2 Capture Zone Analysis VI.2 Above-Ground Groundwater Treatment Systems VI.1 Activated Carbon Adsorption VI.2 Air Stripping VI.3 Advanced Oxidation Process VI.4 Metal Removal by Precipitation VI.5 Biological Treatment VI.3 In Situ Groundwater Remediation VI.1 In Situ Bioremediation VI.2 Air Sparging Chapter VII VOC-Laden Air Treatment VII.1 Activated Carbon Adsorption VII.1 Adsorption Isotherm and Adsorption Capacity VII.2 Cross-Sectional Area and Height of GAC Adsorbers VII.3 Contaminant Removal Rate by the Activated Carbon Adsorber VII.4 Change-Out (or Regeneration) Frequency VII.5 Amount of Carbon Required (On-Site Regeneration) VII.2 Thermal Oxidation VII.1 Air Flow Rate vs.2 Heating Values of an Air Stream VII.3 Dilution Air ©1999 CRC Press LLC VII.4 Auxiliary Air to Supply Oxygen VII.5 Supplementary Fuel Requirements VII.6 Volume of Combustion Chamber VII.3 Catalytic Incineration VII.1 Dilution Air VII.2 Supplementary Heat Requirements VII.3 Volume of the Catalyst Bed VII.4 Internal Combustion Engines VII.1 Sizing Criteria/Application Rates VII.5 Soil Beds/Biofilters VII.1 Design Criteria ©1999 CRC Press LLC Preface The focus of the hazardous waste management business has switched in recent years from litigation and site assessment to remediation. Site restora- tion usually proceeds through several phases and requires a concerted, mul- tidisciplinary effort. Thus, remediation specialists have a variety of back- grounds, including geology, hydrology, chemistry, microbiology, meteorology, toxicology, and epidemiology as well as chemical, mechanical, electrical, civil, and environmental engineering. Because of differences in the formal education of these professionals, their ability to perform or review remediation design calculations varies considerably. For some, performing accurate design calculations can become a seemingly insurmountable task. Most, if not all, of the books dealing with site remediation provide only descriptive information on treatment technologies, and none, in my opinion, provide helpful guidance on illustrations of design calculations. This book was written to address the current needs of practicing engineers, scientists, and legal experts who are employed by industry, consulting companies, law firms, and regulatory agencies as well as university seniors and graduate students in the field of soil and groundwater remediation. It provides prac- tical and relevant working information, derived from the literature and from my own hands-on experiences in consulting and teaching in this field. I sincerely hope that this book becomes a useful tool for the professionals and students working in site remediation. Your comments and suggestions are always welcome, and my e-mail address is jkuo@fullerton. Finally, I would like to take this opportunity to thank Tom Hashman and Ziad El Jack of the Sanitation Districts of Los Angeles County for re- viewing the manuscript and providing valuable comments. ©1999 CRC Press LLC Kuo, Jeff "Introduction" Practical Design Calculations for Groundwater and Soil Remediation Boca Raton: CRC Press LLC,1999 chapter one Introduction I.1 Background and objectives The hazardous waste management business has steadily increased since the early 1980s as public concern led to a vast range of new environmental regulations. During much of this period, a substantial amount of time and expense has been devoted to studying contaminated sites, with much of the expense dedicated to litigation to determine the financially responsible par- ties. However, the focus has switched in recent years from litigation and site assessment to remediation. Site restoration usually proceeds through several phases and requires a concerted, multidisciplinary effort. Thus, remediation specialists have a variety of backgrounds, including geology, hydrology, chemistry, microbiology, meteorology, toxicology, and epidemiology as well as chemical, mechanical, electrical, civil, and environmental engineering. Because of differences in the formal education of these professionals, their ability to perform or review remediation design calculations varies consid- erably. For some, performing accurate design calculations can become a seemingly insurmountable task. The absence of uniformly trained specialists is exacerbated by the con- tinuously evolving remediation technology. For instance, remediation tech- nologies such as soil venting and bioremediation are now generally accept- able to environmental professionals, while just a few years ago they were the subject mainly of research articles. While up-to-date design information is sporadically published in the literature, it is usually theoretical in nature and illustrative applications are rarely given. Most, if not all, of the books dealing with hazardous waste management and site remediation provide only descriptive information on treatment technologies, and none, in this author’s opinion, provide helpful guidance on illustrations of design calculations. Without the proper education, environmental professionals can exert themselves, needlessly reinventing the wheel, so to speak, and err in their ©1999 CRC Press LLC design calculations. This book was written to address the current needs of practicing engineers, scientists, and legal experts who are employed by industry, consulting companies, law firms, and regulatory agencies in the field of soil and groundwater remediation. It covers important aspects of the major design calculations used in this field and also provides practical and relevant working information derived from the literature and the author’s own experience. Realistic examples are used liberally to illustrate the appli- cation of the design calculations. This book can also serve as a supplementary textbook or reference book for university seniors and graduate students who would like to have an overview of remediation design calculations.2 Organization The book is divided into the following chapters: Chapter two: Site Assessment and Remedial Investigation. This chapter illustrates engineering calculations needed during site assessment and remedial investigation. It begins with simple calculations for estimating the amount of contaminated soil excavated and that left in the vadose zone and size of the contaminated plume in the aquifer. This chapter also describes necessary calculations to determine par- titioning of contaminant mass in the different phases, which is critical for remediation design. Chapter three: Groundwater Movement and Plume Migration. This chapter illustrates how to estimate the rates of groundwater move- ment and plume migration. The reader will also learn how to interpret the aquifer test data and estimate the age of a groundwater plume. Chapter four: Mass Balance Concept and Reactor Design. This chapter first introduces the mass balance concept, followed by reaction kinet- ics, as well as types, configuration, and sizing of reactors. The reader will learn how to determine the rate constant, removal efficiency, optimal arrangement of reactors, required residence time, and reactor size for one’s specific applications. Chapter five: Vadose Zone Soil Remediation.
